Entity and Table

An entity is a Java class whose objects are stored as rows. Mark it with @Entity and give it an @Id:

package in.shopease.entity;

import jakarta.persistence.*;
import java.math.BigDecimal;

@Entity                                  // this class is persistent
@Table(name = "products")                // table name (default would be "product")
public class Product {

    @Id                                  // primary key
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;                 // -> column "name"
    private String description;
    private BigDecimal price;
    private Integer stock;
    private String category;

    protected Product() { }              // required by JPA

    public Product(String name, BigDecimal price, Integer stock) {
        this.name = name;
        this.price = price;
        this.stock = stock;
    }

    public Long getId() { return id; }
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
    public BigDecimal getPrice() { return price; }
    public void setPrice(BigDecimal price) { this.price = price; }
    public Integer getStock() { return stock; }
    public void setStock(Integer stock) { this.stock = stock; }
    // other getters/setters ...
}

• Annotated with @Entity, with exactly one @Id (or a composite id).
• A no-argument constructor, public or protected. Hibernate creates objects with it, then fills the fields.
• Not final, and no final persistent methods — Hibernate creates subclasses (proxies) for lazy loading.
• Top-level class (not an inner class).
• Every non-static, non-transient field is persisted by default — you do not need @Column on each one.

@Entity(name = "Product")                  // name used in JPQL queries (default: class name)
@Table(
    name = "products",
    schema = "shop",                          // optional database schema
    uniqueConstraints = @UniqueConstraint(name = "uk_product_sku", columnNames = "sku"),
    indexes = @Index(name = "idx_product_category", columnList = "category")
)
public class Product { ... }